Switch



J. M. BROWN.

swncn.

APPLICATION "LED OCT. a 911- Patented Aug. 2, 1921 Zg; A I 5 I c ..J. Tlc ..v "L 1 5 r f 5 INVVVVVYZ WITNESS-ES BY g a ATTORNEY UNITED STATESPATENT OFFICE.

JAMES M. BROWN,

01: PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE SWITCH.

Application filed October 8, 1917.

T 0 all whom it may concern.

Be it known that I, JAMns M. BnowN, a citizen of the United States, anda resident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in Switches, ofwhich the following is a specification.

My invention relates to switches and par ticularly to such switches asare adapted to so change the connections of an indicating device that itmay be utilized to selectively indicate the voltage of, or a ground on,any of the several phases of a polyphase circuit.

The object of my invention is to provide switches of the above indicatedcharacter that shall be simple and eflective in operation and that shallpermit of selectively associating a single indicating device withseveral circuits or phases of a circuit, or of en tirely disassociatingit from all of them, as desired.

In practising my invention, I provide an indicating device, such as avolt-meter or a lamp, that is connected to a secondary circuit of atransformer, the primary circuit of which is connected in series with,and between, the n'iovable contact arms of two dial switches. Thestationary contact members of the dial switches are so connected to theseveral phases of the polyphase circuit, and to a ground conductor, asto permit energization of the primary winding of the trans former byplacing it across any of the circuits or between any of the conductorsand the ground conductor. Thus, by a very simple andpermanently-connected device, thevoltage of, or a ground on, any of thephases of a polyphase circuit may be readily determined.

Figure 1 of the accompanying drawings is a diagrammatic view of theelectrical connections embodying my invention, when employed inconnection with a three-phase circuit, and Fig. 2 is a similar viewshowing the adaptation of my invention to a twophase circuit.

A transformer 1 has its secondary winding 2 connected to an indicatingdevice 3 that may comprise a volt-meter and a lamp, connected inparallel relation. The volt meter and the lamp operate simultaneouslywith energization of the secondary coil 2, the lamp being adapted tomore readily indicate Specification of Letters Patent.

Patented Aug. 2, 1921.

Serial No. 195,248.

the fact and the volt-meter the amount of energization.

The primary coil 4 of the transformer 1 is connected between movablecontact arms 5 and 6 of dial switches 7 and 8. conductors A, B and (l ofa three-phase system are respectively connected to stationary contactterminals a, I) and c of the switches 7 and H, and a ground conductor Gis connected to stationary contact terminals y of the same.

Vl'hen the movable contact arms 5 and (i are in the position shown, noindication will be given by the device 3. If the arm 5 is moved intoengagement with the contact terminal a, and, at the same time, the arm(3 is moved into engagement with a contact terminal I), the primary coil4 will be energized in accordance with the voltage of phase A-B. Sincethe voltage of the sec ondary circuit of the transformer 1 is a measureof the primary-circuit voltage, both the amount (that may bear anysuitable ratio to the primary-circuit voltage) and the fact will beindicated 1) the devi e 3. Similarly, the voltages of the phases 13-0and All may be determined by placing the arms 5 and 6 in engagement withcontact terminals 6 and c and a and 0, respectively.

To determine a ground in the conductor A, the arm 5 is moved intoengagement with the contact terminal 1 and the arm 6 is moved intoengagement with the contact terminal or c. In case a ground exists,current will flow through the primary coil 4, and the device 3 will beactuated. Similarly, grounds in conductors B and (l may be de terminedby placing one arm in contact with terminal 7 and the other arm incontact with either of the two terminals other than the onecorresponding to the conductor for which an indication is desired.

The operation of my invention, when applied to a two-phase system, andas shown in Fig. 2, is similar to the above, the indicating device beingplaced in proper relation to the various conductors, for the purposes described, by moving the arms 5 and 6 into engagement with the properstationary. contact terminals.

In Fig. 2, the conductors 10 and 10 represent one phase and theconductors 11 and 11 the other phase. Conductors 10 and 11 In Fig. 1,

may be tested for grounds by moving the arm 6 into engagement with therespective terminals connected to said conductors and by allowing thearm 5 to remain connected to the ground, while conductors l0 and 11 maybe tested for grounds by allowing the arm 6 to remain connected to theground as shown and moving the arm 5 into engage ment with the properterminal.

There is obviously no limit to the number of phases in a circuit towhich my invention may be adapted, it bei'ng a matter of arrangement ofthe stationary contact terminals of the switches 7 and 8, only.

While I have shown and described particular forms and arrangements of myinvention, many changes may be effected therein without departing fromthe spirit and scope of the same, as set forth in the appended claims.

I claim as my invention:

1. The combination with an indicating device and a plurality ofcircuits, of a ground conductor, two switches each of which comprisesone movable contact mem her and a plurality of stationary contactterminals, one of the said stationary contact terminals of each switchbeing operatively connected to the ground conductor and the otherterminals being connected to the circuits, a transformer having itsprimary winding connected in series with the stationary contactterminals and its secondary winding connected to the indicating device,and means whereby the movable contact members may selectively engage thestationary contact terminals to determine, by means of the indicatingdevice, a ground on, and the voltage of, any of the circuits.

2. The combination with an indicating device and a plurality ofcircuits, of a ground conductor, two switches both of which may beoperatively connected to said ground conductor or to said circuits and atransformer having its primary winding connected in series with saidswitches and its secondary winding connected to the indicating device,

said switches permitting said indicating device to selectively indicatea ground on, and

the voltage of, any of said circuits.

3. The combination with an indicating device and a plurality ofcircuits, of a ground conductor, two switches each of which comprisesone movable contact member and a plurality of stationary contactterminals, the said stationary contact terminals of both switches beingoperatively connected to the ground conductor and to each side of thecircuits respectively, a transformer having its primary windingconnected to the movable contarf members and its secondary windingconnected to the indicating device, and means whereby the movablecontact members may selectively engage the stationary contact terminalsto determine, by means of the indicating device, a ground on, and thevoltage of, any of the circuits.

In testimony whereof. I have hereunto subscribed my name-this 20th dayof Sept. 1917.

JAMES M. BROWN.

It is hereby certified that in Letters Potent No. 1,385,981, grantedAugust 2, 1921, ujmn the application of James M. Brown, of Pittsburgh,Pennsylvania, for an improvement in Swim-hes," an error appears in theprinted specification requiring correction as follows: Page 2, lines 32and 33, claim 1, for the words "stationai'y contact terminals" readmovable contact members; and that. the said Letters Patent should beread with this correct-ion therein that the same may conform to therecorgi of the case in the Patent Office.

Signed and sealed this 4th day of Oetober, A. 1)., 1921.

[SEAL] KARL FENNTNG,

Acting OQmmiss-io-rM' of Patents.

